Apache Log4j SLF4J Binding allows applications coded to the SLF4J API to use Log4j 2 as the implementation.

Bytecode (Java 8) for Apache Log4j SLF4J Binding is provided in a separate JAR file like log4j-slf4j-impl-2.14.1.jar.

Source Code files for Apache Log4j IOStreams are provided in both binary packge like apache-log4j-2.14.1-bin.zip and source package like apache-log4j-2.14.1-src.zip. You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j SLF4J Binding 2.14.1 below.

⏎ org/apache/logging/slf4j/Log4jMarker.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache license, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the license for the specific language governing permissions and
 * limitations under the license.
 */
package org.apache.logging.slf4j;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;

import org.apache.logging.log4j.MarkerManager;
import org.slf4j.IMarkerFactory;
import org.slf4j.Marker;
import org.slf4j.impl.StaticMarkerBinder;

/**
 * Log4j/SLF4J {@link org.slf4j.Marker} type bridge.
 */
public class Log4jMarker implements Marker {

    public static final long serialVersionUID = 1590472L;

    private final IMarkerFactory factory = StaticMarkerBinder.SINGLETON.getMarkerFactory();

    private final org.apache.logging.log4j.Marker marker;

    /**
     * Constructs a Log4jMarker using an existing Log4j {@link org.apache.logging.log4j.Marker}.
     * @param marker The Log4j Marker upon which to base this Marker.
     */
    public Log4jMarker(final org.apache.logging.log4j.Marker marker) {
        this.marker = marker;
    }

    @Override
    public void add(final Marker marker) {
		if (marker == null) {
			throw new IllegalArgumentException();
		}
        final Marker m = factory.getMarker(marker.getName());
        this.marker.addParents(((Log4jMarker)m).getLog4jMarker());
    }

    @Override
	public boolean contains(final org.slf4j.Marker marker) {
		if (marker == null) {
			throw new IllegalArgumentException();
		}
		return this.marker.isInstanceOf(marker.getName());
	}

    @Override
	public boolean contains(final String s) {
		return s != null ? this.marker.isInstanceOf(s) : false;
	}

    @Override
	public boolean equals(final Object obj) {
		if (this == obj) {
			return true;
		}
		if (obj == null) {
			return false;
		}
		if (!(obj instanceof Log4jMarker)) {
			return false;
		}
		final Log4jMarker other = (Log4jMarker) obj;
		if (!Objects.equals(marker, other.marker)) {
			return false;
		}
		return true;
	}

    public org.apache.logging.log4j.Marker getLog4jMarker() {
        return marker;
    }

    @Override
    public String getName() {
        return marker.getName();
    }

    @Override
    public boolean hasChildren() {
        return marker.hasParents();
    }

    @Override
	public int hashCode() {
		return 31 + Objects.hashCode(marker);
	}

    @Override
    public boolean hasReferences() {
        return marker.hasParents();
    }

	@Override
    public Iterator<Marker> iterator() {
        final org.apache.logging.log4j.Marker[] log4jParents = this.marker.getParents();
        final List<Marker> parents = new ArrayList<>(log4jParents.length);
		for (final org.apache.logging.log4j.Marker m : log4jParents) {
            parents.add(factory.getMarker(m.getName()));
        }
        return parents.iterator();
    }

	@Override
	public boolean remove(final Marker marker) {
		return marker != null ? this.marker.remove(MarkerManager.getMarker(marker.getName())) : false;
	}
}

⏎ org/apache/logging/slf4j/Log4jMarker.java

Or download all of them as a single archive file:

File name: log4j-slf4j-impl-2.14.1-sources.jar
File size: 23635 bytes
Release date: 2021-03-06
Download 

⇒ Source Code for Apache Log4j to SLF4J Adapter

⇐ Source Code for Apache Log4j Commons Logging Bridge

⇑ Downloading and Reviewing Apache Log4j Packages

⇑⇑ FAQ for Apache Log4j